Andrej Pashchenko
@andrejsql.bsky.social
Data Engineer, Oracle Ace Pro ♠ blog.sqlora.com
With online stats gathering, Oracle AI Database captures stats when you use CREATE TABLE AS SELECT A direct path INSERT INTO ... SELECT into an empty table @andrejsql.bsky.social investigates its evolution And finds many restrictions are lifted 26ai
Online Statistics Gathering: Update 2024
Here is an overview of some improvements to Online Statistics Gathering in Oracle Releases 19c-23ai
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🌊💻 MakeIT 2026 & JCON Slovenia 2026 are almost here! Join the Oracle, Java, and open-source community in Portorož, Slovenia for three exciting days of learning, innovation, and networking. 🚀 📍 Portorož, Slovenia | 📅 May 27–29, 2026 🔗 makeit.si #OracleACE
New short blog series on Oracle 26ai CALENDAR functions. Part 2: execution context and the question — Do I still need a time dimension? #Oracle #SQL #26ai #DataWarehouse blog.sqlora.com/en/calendar-...
Oracle 26ai CALENDAR Functions vs Time Dimension
Do Oracle 26ai CALENDAR functions replace a time dimension? A performance and architecture review covering SQL scope, PL/SQL limits, and star schema impact.
blog.sqlora.com
New short blog series on Oracle 26ai CALENDAR functions. Part 1: semantics and implementation nuances. #Oracle #SQL #26ai blog.sqlora.com/en/calendar-...
Oracle 26ai CALENDAR Functions – First Look
A technical first look at Oracle 26ai CALENDAR functions, exploring syntax, formatting rules, fiscal logic, and practical caveats in analytical SQL.
blog.sqlora.com
There are various ways to recall the wonderful conferences of the past year during the slower pace of the Christmas season, such as this one. Who can guess this beautiful place? 🙂 Merry Christmas and hope to see you there next year!
Learning from mistakes is important. Better: learn from others' mistakes. Even better: today we can learn from @danischnider.bsky.social 's ones #doag2025
Storing UUIDs as RAW values is more efficient than strings But RAW can lead to implicit conversions => poor row estimates If you're stuck with string comparisons @andrejsql.bsky.social shows how to improve row estimates with Extended stats Virtual columns
Fix Optimizer Estimate Issues from Implicit Conversions #JoelKallmanDay
Learn how implicit RAW-to-VARCHAR2 conversions in Oracle break histograms, hurt optimizer estimates, and how to fix them safely.
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The long way of #JSON in #Oracle, from 12.1.0.2 until today. Now starting with 23ai and still 15 minutes left. Not bad! You can do it! #HrOUG2025 #HrOUG25
Kim Berg Hansen: SQL ♠ 🤓 👨🍳 🍺@kibeha.dk · 10mo agoWhen I last presented "Invitation to the Wedding of JSON and Relational Data" we were at version 23.4. Now to update it a "little" bit for version 23.9... Oh... There were new JSON features in: - 23.5 - 23.6 - 23.7 - 23.8 - 23.9 Stop, Oracle, Stop! It'll be impossible to finish in 45 minutes!
Tennis before the first session on day 3 of HrOUG with team „Awesome“ and „OMG“. It was great fun. Thanks! #HrOUG25 #HrOUG2025
#joelkallmanday We tend to forget that troubleshooting is mainly just about Clear and Calm thinking.. pdvfirstblog.blogspot.com/2025/10/simp...
Simplicity, Troubleshooting, #JoelKallmanday
TL;DR: You don't have to be a genius to solve problems. And there is no shame in not-knowing or not understanding all the geeky details. Ma...
pdvfirstblog.blogspot.com
New post for #JoelKallmanDay! Ever wondered why the Oracle Optimizer sometimes ignores your histograms? Implicit data type conversions might be to blame. Here’s how to fix it without touching your SQL and with minimal schema impact. #Oracledatabase blog.sqlora.com/en/fix-optim...
Fix Optimizer Estimate Issues from Implicit Conversions #JoelKallmanDay
Learn how implicit RAW-to-VARCHAR2 conversions in Oracle break histograms, hurt optimizer estimates, and how to fix them safely.
blog.sqlora.com
Honored to speak at #HROUG2025 – celebrating its 30th anniversary in amazing Rovinj! 🎉 Huge thanks to the organizers for keeping this fantastic community going for 30 years! 🙏 Let’s put some old SQL myths to the test together! #Oracle #SQL #Optimizer #Accenture #OracleAce
How do I get the test data these days? My #Accenture colleague @cgohmannde.bsky.social explains. #makeit2025
I finish the first day of #MakeIT2025 like I started it: with a session of @andrejsql.bsky.social. This time he talks about parameterized views in Oracle
How can we help the Oracle optimizer to do better with function calls? @danischnider.bsky.social explains. #makeit2025
After the keynote at #MakeITConf, my Accenture colleague @andrejsql.bsky.social shared some interesting insights of table merging. @oracleace.bsky.social
Conferences are always a chance to see my former colleagues of Trivadis again: @andrejsql.bsky.social talking about table merging at #MakeIT2025
MERGE ... RETURNING is now supported in Oracle 23ai. In my view, it deserves more visibility in the documentation — it wasn’t easy to find. Even LLMs still claim it doesn’t exist (some go as far as inventing error codes). Read more: #Oracle23ai #SQL #MERGE #OracleDB blog.sqlora.com/en/merge-and...
MERGE and DML RETURNING clause in Oracle 23ai
Oracle 23ai finally supports MERGE … RETURNING! A long-awaited feature, but still hard to find in the docs.
blog.sqlora.com
Ten years after my first post on the quirks of MERGE and ORA-30926, I took a fresh look at how Oracle 23ai handles it. Clearer error messages, improved diagnostics, and fewer unnecessary restarts. Read the new blog post #Oracle23ai #SQL #MERGE @oracleace.bsky.social blog.sqlora.com/en/ora-30926...
ORA-30926 in Oracle 23ai: What’s Changed?
Explore how Oracle 23ai improves MERGE behavior and error handling, replacing vague ORA-30926 message with clearer, smarter diagnostics.
blog.sqlora.com
Happy to share my new Oracle Certified AI Vector Search Professional certification! BTW, it is free until May 15 2025 #Oraclecertified #ConvergedDatabase catalog-education.oracle.com/pls/certview...
Oracle AI Vector Search Certified Professional
he Oracle AI Vector Search Professional Certification is designed for Oracle DBAs, AI engineers, and cloud developers to unlock the potential of Oracle Database 23ai to build AI-driven applications. T...
catalog-education.oracle.com
Did you know that refreshing HCC-compressed materialized views with atomic_refresh=true can multiply storage usage over time? Small details can have massive impacts. Read the new blog post. #Exadata #Oracle #HCC @oracleace.bsky.social blog.sqlora.com/en/when-comp...
When Compression Expands: The Hidden Pitfalls of HCC
This post explores the behavior of Hybrid Columnar Compression (HCC) in Oracle Exadata while refreshing materialized views with atomic_refresh=true.
blog.sqlora.com
The same topic, the same @danischnider.bsky.social, but something has changed, the stage dimension perhaps? Note: stage dimension is not a new term in data warehousing, Dani is speaking about 😃
Andrej Pashchenko@andrejsql.bsky.social · 2y ago@danischnider.bsky.social explains the performance of views on the big stage of the #DOAG2024
Excited to speak at #UKOUGDiscover24! Do you also believe that collecting statistics in a data warehouse is not a ‘one size fits all’ approach? And that a targeted approach is part of your role as a data engineer? Join my session on 2 December at 16:00. See you there! ukoug.org/page/UKOUGCo...
Mentioned you, your blog und linked to your package SQM_UTIL, @stewashton.bsky.social. Such package is a must have if you consider using SQL Macros. Thank you.
Philipp Salvisberg@salvis.com · 2y agoFirst session at #DOAG2024 by @andrejsql.bsky.social about SQL Macros. Lot of examples and ideas after a short introduction.
The wait is over: #DOAG2024 starts tomorrow in Nuremberg. Want to learn about some advanced techniques and concepts around the practical use cases of #SQLMacros in #oracledatabase? Join me in the very first slot at 8:30
